Treatment of castor-oil



A. SCHWABCVIAN. TREATMENT 0F CASTOR OIL.

APPLICATION F|LED APR.20, 1920.

Patented Mar. 22, 1921.

Y flllllllllnn/ l-l I 1 entre@ sfr/tras tartar @arreso .ALEXANDER SCHWARCMAN, OF BUFFAL, NEW YORK, ASSIGNGJR/ T0 SPENCER KEC'LOGG @t SONS, INC., OIF BUFFALU, NEW YORK, A CORPORATION @EN NEW matassa,

rnna'rrrntrr on Casson-err..

Specication of Letters Patent. lPgmgfglm-,Qd Mam 229 jlgg Application led April 22o, 1920. Serial No. 375,318..

To all wtom it may concern:

Be it known that li, ALEXANDER SorrwAno- MAN, a citizen of the United States, residing at Bu'alo, in the county of Erie and State of New York, have invented certain new and useful improvements in the Treatment of Castor-Uil, of which the following is a specification.

rllhis invention relates to the treatment of castor oil; and it comprises a process of re- `iining castor oil and rendering the same neutral wherein such castor oil is treated with about the amount of caustic soda solution necessary to combine with the free acids present and thoroughly agitated, and the oil is thereafter washed with a spray of water at or about the boiling temperature vuntil soluble soda soaps are removed, the washed oil being thereafter dried or freed of water; all as more fully hereinafter set forth and as claimed.

lnthe treatment of vegetable oils for refining the same it is a customary practice to add caustic soda solution and agitate, thereafter allowing the mixture to settle to deposit the soda salts 'for soaps as 'llhis treatment renders the oil neutraland carries down mostlof the dissolved or suspended impurities; rlhe process is however not applicable to castor oil, since the bodies produced by reaction of caustic soda with the free fatty acids of castor oil are soluble in the. oil itself. On adding a caustic soda` lye to castor oil in about the amount red quired for neutralization, therefore, there is no separation; the mass is simply rendered somewhat thicker but no separation vofimpurities occurs. refining of castor oil is generally done by more complicated, less e'ective methods. lt is, for example, quite diiicult by known methods to remove the acidity of low grade castor oil to render it better adapted for use as a cylinder lubricant in gas engines. lt is also dimcult, even with the best grade of castor oil,'to produce a tasteless and odorless article.

lt is the object of the present invention to provide a simple, ready, economical method of refining castor oil whereby it may be completely freed of acidity, taste and odor. To this end ll treat the castor oil with about the amount of caustic soda solution necessary to neutralize the free fatty acids as determined foots y For this reason in the art by analysis. llt is better to do this without heating-to avoid action of the soda o-n the neutral oils. solution of 14o to 25 Baume caustic soda may be used. rllhe caustic soda solution and the oil are thoroughly agitated together until uniform admixture is obtained. It is desirable to use the exact amount of soda necessary since if too little beused some of the acids will be left while if too much isI used some oil will be saponiiedor decomposed, castor oil being quite sensitive to the saponifying action of alkaline solutions, even in the cold. Because of this sensitive character it is desirable that agitation -or incorporation be as rapid as possible. No separation of soaps or impurities occurs at this stage of the operation; the mixture will give no substantial deposit onbeing allowed to stand.

l have found, however, that if the oil be now somewhat raised in temperature, say to about 180 F, and then sprayed with finely divided hot water somewhere near the boiling point, the soaps and soda compounds can be thoroughly washed out of the oil with the production of a pure neutral oil. With the water go many of the impurities to which the taste and odor of crude castor oil are due. Heating the oil after the incorporation of alkali with the oil is not harmful where the right amount of soda has been used. lf more than the right amount has been used, there will be a concomitant loss of oil. With less than the right amount, or without thorough agitation in the mixing step some acid may remain.

l find it is best during this washing operation to place theoil in a long narrow tank and introduce water at just below the boiling temperature in the form of a very ine rain or spray falling through the oil. rllhe falling dropsof water very eHectually clean the oil of the dissolved soda soaps and other impurities. I Ordinarily l wash a number of times, using about 5 per'- cent. of water by volume eacln time. Each portion of wash water as it reaches the bottom of the column of oil separates cleanly and perfectly; there is very'. little loss of oil, if" any, as foots. Usually 5 or 6 washings are sufficient except with unusually low grade oils.

- The watery liquid collecting at the bottom of the body of oil is-essentially a water solution of thesoda soaps of the free acids of the castor oil, carrying more or less suspended coagulated albuminoids, dirt, etc. The solution may be readily clarified or separated fromsolid matte-r by filtration or decantation. The solution so obtained is a neutral soap solution which mayfbe used for various purposes; or it may be broken up by the addition of a little acid to set'free the fatty acids, (ricinoleic acid,y etc.). With prq'per operation very little neutral oil is taken away with the water solution.

After the described operation the oil is left in a wet state and it is necessary to remove the contained water. This water T may remove by blowing with air while still hot. This treatment has the additional advantage that any residual volatile constituents not taken out by the soda are thoroughly -removed from the oil. yMuch of the taste and odor of castor oil are due to such volatile bodies. After drying, the material left is,`

even in thecase ofrather low grade oil, a high grade preparation as regards odor and taste; and it is perfectly free of acidity.

After drying or dehydration, the o1l may next be agitated with a little fullers earth, boneblack or other suitable decolorant or purifying agent. It is now a clean, permanent and neutral oil.

Tn. the accompanying drawings l have shown one form of an apparatus suitable for the performance of my process.

Figure 1 is a top plan view;

Fig. 2 is a vertical longitudinal section; and

Fig. 3 is a transverse section.

Tn the drawings element 1 represents a tank, advantageously lll-shaped in construction, provided with spiral stirrer or agitating device 2, having the shaft 3 journaled `through stufling box 4 at each end with pulley and belt froln a source of power (not shown). The tank is provided with a jacket 5 in order that the contents may be heated by means of steam introduced into the acket I through inlet 6 with outlet at 7. The contents of the tank after treatment ma be removed through the valved outlet 8. A ove the spiral conveyer, the tank is provided with the spraypipe 9 having the inlet 10 connected to a source of supply (not shown). Lateral pipes 11 are attached to the main pipe and the main and lateral pipes are provided with perforations in order that the l contents of the main tank may be sprayed of about 140 to 25o Baume. The stirrer is started and revolved at a rapid rate. After the mixture of oil and causticv soda has been thoroughly agitated, its temperature is raised to about 180 F. by admitting steam to the jacket through inlet. 6, and it is then sprayed with hot water from the pipes 9 and 11. This causes a thorough washing out of the soaps and soda compounds. This spraying operation may be repeated as many times as may be desired. The watery liquid collecting at the bottom is drawn off through valved outlet 8 after each such washing, the stirrer being stopped for the purpose of allowing the liquid to settle. In order to remove the last traces of water and dry the oil, air is then admitted through pipe 12, during agitation and the maintenance of the temperature 'of the oil, heat being supplied by the steam jacket.

The eiiect of adding a little soda solution of moderate strength and thoroughly agitating is to produce a more or less homogeneous blend or solution of the two liquids; thereby neutralizing free fatty acids present and formin ln the described process this blended more or less homogeneous product is first treated with a limited amount of hot water to produce a readily settling material. After separating this from the body of the oil, further corresponding dissolved soda soaps.

successive small portions of water are added comprises agitating it with about the amount of caustic soda solution necessary-to neutralize the free fatty acids present, raising its temperature and then spraying with a little hot water in such manner as to produce a descent of said water in. a nely divided state through the oil body.

2. The process of refining castor oil which comprises agitating it with about the amount f of caustic soda solution necessary to neutralize the free fatty acids present, raisingits temperature, then spraying with a little hot water in such manner as to produce a descent of said'water in a tinelydividedistate through the oil body and thereafter drying vthe washed oil. v.

3. The process of refining, castor oil which comprises agitating it with about the amount of caustic soda solution necessary to neutralize the free fatty acids present, raising its temperature, then spraying with a little hot water insuch manner as to produce a descent iso naraea of said water in a finely divided state through the oil body and thereafter drying the Washed oil with air.

4. The process of refining castor oil which comprises blending such castor oil with a limited amount of soda solution of moderate strength, thereby neutralizing free fatty acids present and forming corresponding dissolved soda soaps, treating the blended material with a limited amount of hot Water with thorough agitation and settling out the produced aqueous material containing soda soaps.

5. The process of refining castor oil which comprises blending such castor oil with a 15 limited amount of soda solution of moderate strength, thereby neutralizing free fatty acids present and forming corresponding dissolved soda soaps, treating the oblended material with a limited amount of hot Water 20 With thorough agitation, settling out the produced aqueous material containing soda soaps, washing the oil with hot .Water and finally drying.

In testimony whereof, llax m signature. 25

ALEXANDER SCHWCMAN. 

